Chalkboard having curved writing surface



June 17, 1958 A. BATZDORFF CHALKBOARD HAVING CURVED WRITING SURFACE Filed July s, 1956 I I I INVENTOR. ALFRED BATZDORFF XWA Qua ATTORNEY UnitedStates Patent CHALKBOARD HAVING CURVED WRITING SURFACE Alfred Hatzdortf, Langhorne, Pa., assignor to Robin & Haas Company, Philadelphia, Pa., a corporation of Delaware Application July '3, 1956, Serial No. 595,623

2 Claims. (Cl. 35 -63) The present invention relates to improvements in boards of the type upon which writing and other markings are to be applied with chalk or the like. Such boards will hereinafter be referred to as chalkboards.

A particular object of this invention is to provide a relatively large writing surface comprising a permanent installation on a wall or the like to which surface markings may be applied with a minimum of effort. This is accomplished by concavely curving the outer surface of the board so that writing fatigue is substantially reduced in that all parts of the surface may be reached without undue strain upon the writer.

Another object is to provide a curved chalkboard that may be permanently installed with relative ease.

Still another object is to provide a mounted chalkboard having a concavely curved writing surface, the concaved sheet being out of contact with the wall supporting it. This feature not only provides space between the writing surface itself and the supporting wall through which air may circulate to reduce or eliminate problems due to heat differentials and humidity conditions but also, in view of the slight cushioning effect incident thereto, provides far greater writing comfort. Markings upon the curved surface may be more easily viewed since light reflection is substantially reduced and the distance between the entire writing surface thereof and the readers eye is more uniform, reducing the need for constant refocusing, thus substantially eliminating reading or eye fatigue.

Other objects and advantages will be apparent from the following description of an illustrative embodiment which, taken with the accompanying drawing, points out the salient features of this invention.

Fig. l is a perspective View of a chalkboard installation.

Fig. 2 is a section taken on line 22 of Fig. 1.

Fig. 3 is a section taken on line 3-3 of Fig. 1.

Fig. 4 is a section taken on line 4-4 of Fig. 1.

In the figures, 5 indicates a wall or other surface upon which the chalkboard assembly is mounted. The assembly comprises essentially a curved sheet 6 having a concaved outer writing surface held between an upper horizontal strip 7 and a lower horizontal strip 8, the inner lengths of each of which are attached to the surface 5 by L brackets 9 screwed to the surface and to said strips, respectively.

The lower strip 8 is provided with a groove 10, along its length, into which is fitted the lower edge of curved sheet 6. The upper strip 7 is routed out near its outer extremity to accommodate the upper edge of curved sheet 6 which 2 is secured in place by a holding strip 11 fastened in the routed portion of strip 7.

Curved sheet 6 is maintained securely between strips 7 and 8 by guy wires 12 provided with tension springs 13 secured to strips 7 and 8 by screw eyes 14 and 15, respectively. Tension may be individually adjusted through guy wires 12 and springs 13. For instance, the wires 12 may be equipped with turnbuckles (not shown). The turnbuckles may be placed, for example, between the 'lower extremities of the wires and the upper extremities of the springs, and thus may be reached through cut out hand holes 16 provided in lower strip 8. The guy wires 12 are so placed that slight contact is made with the back of curved sheet 6 at the center portion thereof, and are horinzontally spaced along the length of sheet 6. Also, for holding chalk and erasers, there is provided in lower strip 8a trough 17 extending the length thereof.

As additional support or securing means, if the size of the installation warrants, vertical bracing members 18 or alternative angular bracing members 18 (the latter in dotted lines) shown in Fig. 3 may be incorporated into the assembly. There also may be provided, as a part of the assembly, end cover members 19, one of which is shown at the right end of Fig. 1 and more in detail in Fig. 4.

The curved sheet 6 may be of preformed plastic material. It is customary, however, to use a flat sheet cut to size and spring it into place. For example, the plastic chalkboard as shown in United States Patent No. 2,522,351 may be formed to the desired curvature and utilized. Such material is readily adapted to installations as here disclosed in that it may be curved or otherwise formed by application of heat. Upon being subsequently cooled, it retains the shape acquired during the forming operation. It should be clearly understood, however, that this invention is not limited to the use of plastic material as the curved sheet upon which markings are to be made. Any suitable sheet material having a concavely curved outer surface upon which markings may be applied with chalk, for example, may be used.

What I claim is:

l. A chalkboard assembly comprising a sheet curved along one of its dimensions, supports for said sheet at the References Cited in the file of this patent UNITED STATES PATENTS 379,915 Story Mar. 20, 1888 1,827,389 Friend Oct. 13, 1931 2,498,641 Beckwith Feb. 28, 1950 2,522,351 Egolf Sept. 12, 1950 2,541,497 Buxbaum Feb. 13, 1951 

